Cathode-ray tube



E. K. KARLSSON CATHODE-RAY TUBE July 8,

Filed NOV. 13, 1950 Patented July 8, 1952 1 2,602,903

iUNITED STATES PATENT; OFFICE 3 k CATHODE-RAY TUBI I I 'Elof Karlssong Moiine, 111., assignor of' onethird to Kenneth T. Snow, Oak Park, Ill. ApplicationNovember 13, 1950, Serial No. 195,497 1 I 7Clahns. (c1. 313-92) 2 I This invention relates to a new and improved and :a back wall'orneck end l3 'of tnetnbewu; cathode-ray tube. An annular flange [4 is disposed around the rear A principalobject of this invention istoproannular periphery of the portion [2 and abuts vide means in a cathode-ray tube for receiving a a similar annular flange [5 extending around the true focused picture throughout its full scope it periphery of the forward portion of the back making it feasible fordirect viewing or projection. wall I3. A- clamp i6 is arranged and constructed An important object of this invention is the to join the flanges l4 and I5 in vacuum tight provision of meansin a cathode-ray tube for abutting relationship. receiving color impulses and transmitting there The semi-spherical front portion [2 of'the frcma truecolorpicture. v} 10 envelope hasa cylindrical projection ll formed. Another important object (of-this invention "is at thefront end thereof. An annular'fiange l8 to supply a cathode-ray tube with color filter is provided around the circumference of the outer means built therein. v H I j a front end of the cylindrical projection l1 against A further important object of this inventionis which is placed a picture or light transmittin to provide a cathode-ray tube with acombination 5 glass or projectinglens' [9. A clamp extends light filter and picture retentive phosphor surar the ahhlllerflange 18 end the circlimfele face. I ence of the lens [9 to hold the lens in centered A still further important object of this invenposition over theend of the cylindrical 'projection tion is the provision of color filter means in a l! in sealing relationship.

cathode-ray tube and means externally of said 20 An electron gun 2| is disposed at the rear of tube for effecting rotation of said color filter the cathode-ray tube In and is carried in the means. back wall or neck l3 of the tube. The center'of Another and still further important object of the gun desig et d by t e u ra 15 t e Or this invention isto provide a plurality of external of an oscillating electron beam which is adapted magnetic means operable to clutch the drive ofa to deliver the transmitted picture: we viewer: synchronous motor with a colorfilter wheel dis- The center 22 constitutes the center of the semiposed withina cathode-ray tube. 1 spherical front portion l2 of the cathode-ray Stillanother object of this invention is to tube. i 7

supply intermittently engageablemagnetic clutch A bracket 23 is clamped to the gun 2| and means for effecting synchronization. of color extends forwardly and downwardly as shown in impulse transmissions with a color filter Iwheel. Figure l term a in a Sleeve 24 for .i y

Qther and further important job'ject 'iiwill receiving a shaft 25 which is fixed to a color become apparent from thedisclosuresin the folfilter wheel 26 at its center 21 by a rivet type lowing specification and accompanying drawing. hub 28 The color filter wheel is dish shaped QIn the drawings: and is-a perfect part ofa sphere which is con- Figure 1 is a transverse sectional view of the ce t c wi the h si or ope sp ere cathode-ray tube of this invention. i and thus also has the same center 22 as the elec- Figure 2 i .a, plan evigw. of t color tron gun 2|. Acollar 29 is fixed to the shaft 25 employed in this invention anda vie d on the by reason of a radially extending pin 30 and-this line"2--2 of Figure 1. H I 40 assembly provides for the journal bearing of the Figure 3- is an elevational vi w of th magnetic color filter wheel within the sleeve 24.

clutch of .this invention and as viewed ou the The filter W l 26 i cl des a plurality line 3 -3 of Figure 1. y p 7 g of segments 3!.32. 33 and designating the The reference numeral in indicatesgenerally 01 filter portions e s e nhlue andwhite a cathode-ray tube used in television receivers or r sp ctiv l These s ts sph r portions the like. The cathode-ray tube of this invention of t Color Wheel are st s wn in Fi ure 2- is adapted for useas a direct viewing video tube ac of the 00101 Segments portions is or aprojection type video tube wherein thepi'cciently la in itself Cover the front po ti ture received may be projected on an auxiliary 0f the cathode-ray-tube' b hin the picture glass screen s a I9 and inasmuch as the color wheel is a part of The cathode-ray. tube it includes an envelope tr sp r dth center of t p r s Hot non-magnetic material. .This material may coincidental with the center 22 of the electron be glass, ceramic material, or non-magnetic n there is a true focus of the electron beam metal, such as brass or thelike. The envelope on all poi ts of the color filter inasmuch as all ll'oonsists'of'a semi-spherical front portion I2 points on t is filter are equi-distant from the 3 center of the electron gun 2|. The color filter wheel not only performs the function of filtering out certain of the colors to produce a color picture but it also performs the function of receiving the picture. A phosphor coating 35 is provided over the interior of the dish shaped color wheel and provides for the retention of a picture projected thereon bythe electron gun 2| sufiiciently long so that the viewer is ablefto properly see a complete picture. The color wheel is rela tively thin and the coating of phosphor directly on this extremely thin color Wheel eliminates almost entirely diffracted light which has hereto fore accompanied all television picture tubes. The color wheel of this invention is adapted to receive the picture directly on the several phosphor coated segments thereof in succession in the. order that the color impulses are transmitted contact points 61, 68, 69, and H3 is joined with the electrical brushes 62, 63, 64, and 65 respecfrom the transmission station. The picture is A then viewed either directly thro h a front viewing glass-or may be projected onto a screen through alens I9whereupon the picture can be enlarged manyjtimes and because of the-inher-' in Eigures l and-2. The button 36 is fastened to i the dish shaped wheel at a position spaced from thecenter of the, wheel which carries the shaft about which the wheel rotates. A second button 31 of1non-magnetic material is fastened to the;colorfilterwheel 26 at a position diametrically opposed'to the magnetically chargeablebutton 35 and is employed for the purpose of balancingthe color wheel. This completes the'various'elements thatare disposed within the'vacuum cathode ray tube; It should of course be realized that the, color filter wheel of this, invention may be driven by. motor or other means within the tube but in the more desirable location the source of power is located without the tube so that it may beeasily. serviced. e 3,

. As best shown in Figure liasynchronous motor 38 drives a shaft 39 at a uniform speed. A magnetic clutch 4B is fastened to the motor driven shaft ailthrough the medium ofthe frame structure. of the clutch 40. j-

A, plurality offsolenoids 42, 43, 4 4, and are fixed to the rotating frame structure 44 in acir with path .therearound. Each of the solenoids 4-2 p.45 inclusive includes an iron core or the like 4.5; 47,, 4 8, and 419 respectively projecting from the solenoids toward the cathode-ray tube envelopel I. of this, invention. The, cores 48, 4T,- 48 and 49 are, positioned closely adjacent the non-magnetic semi-spherical envelope housing l2 -and are in alignment with the magnetically chargeablebutton 36 and also thenon-magneti'c button 31'.-

Slip rings'5ll, 5:1, 52 and 53 are longitudinally spaced apart and are fixed to but insulated from the motordriven shaft 39' at a position closely adjacent the magnetic clutch 40. A lead wire 54 is adapted to run centrally of the driven shaft 39 for the purpose of joining the slip ring 50 with the solenoid 42-. Similarly the wires 55, 5t, and 511cm the slip rings 5:, 52', and 53' with the solesome 4e, 44, and 45 respectively. All of the lead wires 54 to- 5-1- inclusive run centrally of the. shaft 39 and are insulated onefrom the otherr Similarlylead wires 58, 59, 69, and 6t join the solenoids 42,43, 44, and 45 with the circuit ground which in the presentinstance is the frame structively. As previously stated each of these brushcs engages one of. the sliprings 50 to 53 inclusive. A rotary'switcl'i arm i5 is pivoted at F6 on the plate 66 and is capable of being rotated thereflaround' to engage any one of the circumferentialraytube; is actuated by the electron gun 2i re-f solvingtransmitted impulses and-delivering these impulses'byoscillation of the gun across the receiving picture-color filter designatedby thenumeral 26. "In the operation of: tube in the delivering of purely black and whitepicturesthe whitesegment 34 of the color-wheel 26- is maintained in the'position over the field of travel of the electron be'arndeliveredby the electron gun 2| and that portion of the tubeimmedi'ately behind the picture, glass [9; The white or transparent portion of the color wheel or the color filter wheel 26 is provided with the phosphorescent coating 35 as are all of the segments of the color filter wheel. Inasmuch asthe segment 34 of the picture receiving wheel- 26 is spherical in shape andallthe points thereof are equi-distant from the center 22 of the electron discharging gun 2| there will be imposed on that segment a true-non-distorted picture which, may be directly viewed or which maybe projected-through the picture glass or light transmitting; lens 19; to areceiving screen. The picture thus projected and enlarged will be a true reproduction of the picture-transmittedbyreason ofthe lacl; of distortionof the picture priorfto projection Y In, the operation of the device as a color receiving. cathode-ray tube the color filter wheel 26 is rotatably driven by reason of the synchronous mqtor' tfi and the magnetic clutch 4!); One of the solenoids 42, 43, 44, or i5 is energized with electrical energy whereby thecore 45, 41,- 48, or 49' of the particular solenoid projects a magnetic field which passes through the non-magnetic shellor envelope l2 and charges the magnetically chargeable button 36 whereupon the motor driven magnetic clutch 40 will drag the colorfilter wheel- 26; around its shaft 25; The shaft 25lie's on'the same axis'as the motor driven shaft 39 and thus there is a free rotational movement of the color filter-wheel 25- by the synchronous 'motor' '38 through. the medium ofthe magnetic clutch 40. The filters of the color filter wheel should be identical with the filters employed-in the transmitting. oi. the colorimpulses and further the receiver filters mustnbe positioned in timed relationship with the transmission of the correspond-: ing color pictures. In other words the red: color filter-Al. must be in apositionto receive the. pic'- ture: asdischarged by the electrongun 2i atthat moment: when the red filtered picture: isbeing transmitted. and similarly the green and blue undesirable occurrences.

filtered pictures must bereceived' by the corresponding,v filters 32 and 33 ofthe tube of this invention? simultaneously with the transmission of the'picture filtered for those particular colors. Thus the color filter wheel must be rotated. at a constant speed identical with the speed of rotation of the color filter wheelof the transmitter, The synchronous motor 38 of this. inventionpi designed and constructed to operate at such a constant speed which is identical to the speed of rotation of the color filter wheel employed at the transmitting studios. In order, to synchronize the color filters of this receiving tube with the color filters of the transmitter the rotary switch arm-r15 is moved to any one of the electrical contact points 61, 68, 69, or to effect an energizing of a different one of the solenoid 42, 43, 44, or 45. Thus it is within the power of the operator of this device to actually effect a stopping of the color filter wheel for the space of one segment or four segments as desired by alternately energizing the several solenoids and thus it is possible and very easy to accomplish a synchronizing of the transmitted color picture with the received color picture. In any event the energized solenoid, which ever one it may be, will send out .a magnetic line of force causing a drag on the magnetically chargeable button 36 to pull the color filter wheel 26 around on its shaft 25. It should be understood that the color filter wheel 26 may simply be composed of three segments for the three basic colors red, green and blue or may be divided into six segments or any number of segments in order to accomplish the desired results depending upon the color picture that is being transmitted. It may be desirable to have two series of the three basic colors that is red, green, blue, red, green, and blue. In the color pattern of the filter wheel 26 as shown it is possible to leave the switch arm off of any of the contact points 61 to 10 and thus hold any of the several filter segments in position over the electron gun 2| whereby any single color picture may be provided on the viewing screen whether it is a direct view or projected screen.

The cathode-ray tube of this invention produces an image with a high degree of definition with the result that the image can be projected and enlarged without any blur whatsoever. Further there will be no color or rainbow fringes or overlapping of colors because the color filter constitutes a part of the phosphor coating and this lack of space between the filter and the picture receiving phosphor coating prevents these The apparatus of this invention is relatively small and can be housed in any of the present day conventional television cabinets.

Numerous details of construction may be varied throughout a wide range without departing from the principles disclosed herein and I therefore do not propose limiting the patent granted hereon otherwise than as necessitated by the appended claims.

I claim:

1. A cathode-ray tube comprising an envelope, a picture glass at one end of said envelope, an electron gun at the opposite end of said envelope, means arranged and constructed to receive color transmitted impulses and impart a color picture to said picture glass, said means comprising a plurality of color filters disposed at intervals in timed relation with the transmission of color impulses between said electron gun and said picture glass, said color filters having a phosphoreselectron gun, each of said color filters comprising a portion of said sphere part corresponding in size to said picture glass. 2. A cathode-ray tube asset forth sphere part about anaxis spaced from said picture glass to successively present each of the pluralitypf color filter sphere portions to the scope of said electron gun; 7

3. A cathode ray tube comprising an envelope, a picturegl'ass at one end oij's'aid'-'envelop'e, an

electron gun at the opposite end of said envelope;

means arranged and constructed to receive color transmitted impulses and impart a color picture to said picture glass, said means comprising a plurality of color filters disposed at intervals in timed relation with the transmission of color impulses between said electron gun and said picture glass, said color filters having a phosphorescent coating capable of picture retention, said color filters arranged and constructed as a part of a sphere having its center coincident with said electron gun, each of said color filters comprising a portion of said sphere part corresponding in size to said picture glass, means for rotating said sphere part about an axis spaced from said picture glass to successively present each of the plurality of color filter sphere portions to the scope of said electron gun, said means for rotating said sphere part including a synchronous motor, said synchronous motor positioned outside said cathode-ray tube, magnetic means rotatably driven by said synchronous motor arranged and constructed for imparting drive to said sphere part, said magnetic means comprising a support, a plurality of solenoids equal in number to the plurality of color filters and spaced at regular intervals about a circle on said support, means for individually actuating any one of said plurality of solenoids, and a magnetic button on said sphere part spaced from said rotating axis, whereby the individually actuated solenoids act as clutches between the synchronous motor and said sphere part.

4. A cathode-ray tube comprising a substantially semi-spherically shaped envelope of nonmagnetic material, a projection lens at one end of said envelope, an electron gun disposed at substantially the center of said semi-spherically shaped envelope and at the opposite end of said envelope. and a color filter means rotatable within said envelope between said electron gun and said projection lens.

5. A cathode-ray tube as set forth in claim 4 in which the color filter means includes a part of a sphere and is journally carried on an axis spaced from and to one side of said projection lens whereby the color filter means sphere part extends across said projection lens.

6. A cathode-ray tube as set forth in claim 5 in which picture retentive phosphors are affixed to said color filter means sphere part.

'7. A cathode-ray tube comprising an envelope, a picture glass at one end of said envelope, an electron gun at the opposite end of said envelope, a wheel journaled for rotation within said tube and having a portion thereof disposed between the electron gun and the picture glass. a plurality of color filters carried by said wheel, means for rotating said wheel comprising a synchronous motor positioned outside said tube, magnetic means rotatably driven by said synchronous ln'ola lm 1 in whichmeans is provided .for rotating said meter. arranged and. constructed: for" impartixlgv support, means for individual-1y actuating any one;

of said plurality oi solenoids; v and .a;magnetic.b utton onvsaidwheel, whereby the individually'actuatedfsolenoidse act: as clutches-kbegtweemthe65m:-

chronousmotor-and said wheel- ELQF KARI-Seem, v

REFERENCES CITED" V he follpwing references-Meet recordi'n. the

filepf this patent:

Number V UNITED STATES PATENTS 7 Name'- Date Rudenberg" Nov. 14,1933 Schmidt-Otis et a1. Sept. 12;.1939 Crosby Sept. 29, I942 Longerich Nov; 30; 1943.. Doncas ter Jan. 18;.194Q Szegho June 2-4;- 19437 Schroeder Aug. 10;, 1-948- Szegh0- Feb. 1, 19 49.

Number Amdurcky Aug; 29-, I950 

